This invention relates to motor driven hydraulic systems, and more particularly, to a motor mounting arrangement for use on a hydraulic system which is externally affixed to a motorized vehicle, where the hydraulic system is used to manipulate a snowplow blade.
Motor driven hydraulic systems have been provided heretofore and generally as shown in Pat. No. 3,773,074 to Miceli, for example. Such hydraulic systems are comprised of a motor which is mounted to the body of a hydraulic system at a suitably designed mounting location. The motor typically drives a hydraulic pump which pressurizes the fluid within the system. The pressurized fluid is then used as a source of mechanical power for use in applications described hereinafter.
Hydraulic systems of the foregoing design are well known and regularly employed in a wide variety of applications. Many such applications incorporate this system into a motorized vehicle, where the system is used to provide mechanical power to cylinders which, in turn, manipulate an attached implement. Such applications include warehouse lift trucks, farm tractor implements, construction and earth moving equipment, and snowplow attachments. In each application, the manufacturer designs the system with a specific target for the amount of mechanical power to be output by the system. For instance, the manufacturer may want the system to have the capacity to lift a one ton object, or move five cubic yards of gravel with one push. The manufacturer will normally consider the influence of additional factors, and then design and size each of the components of the system accordingly. Such additional factors may include cost of the components, duty cycle, and conditions of use. The weight given to each factor varies from application-to-application and from manufacturer-to-manufacturer.
The conditions of use are particularly influential with regard to hydraulic systems that are externally affixed to motor vehicles for use with snowplows. Such systems are subjected to abuse which is not present in the other previously described applications. In these other applications, the hydraulic system is normally housed within one of the compartments of the vehicle or at the very least the hydraulic system is shielded by the vehicle's body. This is not so with the hydraulic system in this application, that is, one used to manipulate a snowplow blade. Here, the hydraulic system is attached to the front of a truck or other vehicle where it is exposed to extreme weather conditions. Additionally, even though plowing is done at relatively low speeds, the snowplow blade traveling across the uneven surface of a driveway or parking lot creates significant jolting, jarring and vibration throughout the entire hydraulic system. Furthermore, a hydraulic system of the foregoing description is rigidly mounted to the frame of the vehicle. This is necessary to provide the proper strength for the snowplow, but this makes the installation and removal of the heavy hydraulic system a difficult and time consuming task. As such, the system is routinely left on the vehicle year-round, even though the snowplow may have been removed at the first sign of spring. The vehicle is then used in an everyday fashion, many times including travel on highways or at highway speeds, during which time the hydraulic system mounted on the front of the vehicle, without the protection of the snowplow blade, will be subject to severe impact from stones and asphalt chips moving at highway speeds. In the other applications, the systems are installed on vehicles which do not regularly, if ever, travel at highway speeds. Furthermore, the shielding previously described for these other applications provides protection for the system in the event that it is transported at high speeds. In the end, the hydraulic system for a snow plow incurs abuses not commonly endured by other applications. For this reason, components normally used with success in other applications cannot survive in a hydraulic system for a snowplow.
The foregoing description of the conditions of use of the hydraulic system of the snowplow indicates the abusive nature of this particular application. As a result, only components with sufficient quality and qualified construction will withstand such abuse. Of particular susceptibility is the electric motor which drives the hydraulic pump. When the need eventually arises for the motor to be replaced, the repair person may, intentionally or not, replace the motor with one of lesser quality, durability and/or construction, or one of different speed or power output. This is a common occurrence because motors of any particular size are available in a wide variety of quality, construction and horsepower ranges. This greatly increases the possibility that a motor of insufficient quality, durability and/or construction will be installed on the hydraulic system, or that a motor with excessive speed or power output will be installed. Either case is potentially dangerous to the operator, and can also cause damage to the equipment or the manufacturer's reputation.